From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:58341 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422762AbbD2L5u (ORCPT ); Wed, 29 Apr 2015 07:57:50 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 3373A20DC2 for ; Wed, 29 Apr 2015 07:57:50 -0400 (EDT) Subject: FAILED: patch "[PATCH] sched/idle/x86: Optimize unnecessary mwait_idle() resched" failed to apply to 3.10-stable tree To: bitbucket@online.de, bp@alien8.de, efault@gmx.de, hpa@zytor.com, ibmalone@gmail.com, jwboyer@redhat.com, len.brown@intel.com, lenb@kernel.org, mingo@kernel.org, peterz@infradead.org, stable@vger.kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org Cc: From: Date: Wed, 29 Apr 2015 13:57:48 +0200 Message-ID: <143030866824337@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 3.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From f8e617f4582995f7c25ef25b4167213120ad122b Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Sat, 18 Jan 2014 17:14:44 +0100 Subject: [PATCH] sched/idle/x86: Optimize unnecessary mwait_idle() resched IPIs To fully take advantage of MWAIT, apparently the CLFLUSH instruction needs another quirk on certain CPUs: proper barriers around it on certain machines. On a Q6600 SMP system, pipe-test scheduling performance, cross core, improves significantly: 3.8.13 487.2 KHz 1.000 3.13.0-master 415.5 KHz .852 3.13.0-master+ 415.2 KHz .852 + restore mwait_idle 3.13.0-master++ 488.5 KHz 1.002 + restore mwait_idle + IPI fix Since X86_BUG_CLFLUSH_MONITOR is already a quirk, don't create a separate quirk for the extra smp_mb()s. Signed-off-by: Mike Galbraith Cc: # 3.10+ Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Ian Malone Cc: Josh Boyer Cc: Len Brown Cc: Len Brown Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1390061684.5566.4.camel@marge.simpson.net [ Ported to recent kernel, added comments about the quirk. ] Signed-off-by: Ingo Molnar diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index da06f741d2a6..6ad8a6396b75 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -428,18 +428,22 @@ static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c) static void mwait_idle(void) { - if (!need_resched()) { - if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) + if (!current_set_polling_and_test()) { + if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) { + smp_mb(); /* quirk */ clflush((void *)¤t_thread_info()->flags); + smp_mb(); /* quirk */ + } __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); if (!need_resched()) __sti_mwait(0, 0); else local_irq_enable(); - } else + } else { local_irq_enable(); + } + __current_clr_polling(); } void select_idle_routine(const struct cpuinfo_x86 *c)